Microstructure and vacuum impregnation response of citrus peels

Vacuum impregnation (VI) technique represents a good choice for developing high quality peel products or food ingredients, taking advantage of their interesting, composition. increasing their sweetness and improving their sensory acceptance. Vacuum impregnation response of citrus peels (orange, mandarin, lemon, grapefruit) were analysed using different isotonic solutions. Sample deformation and impregnation levels in line with pressure changes have been determined. Peel microstructure has also been analysed (by Cryo-SEM) before and after the VI process. Results reflect a high capacity of impregnation (45-70% of initial sample volume) and swelling (12-33% of initial sample volume) of the peels. The great porosity of the albedo zone is responsible for this behaviour. In this zone, the great intercellular spaces can be flooded by an external solution. and this makes the citrus peels highly suitable to obtain new products with improved functionality and sensory acceptance. (C) 2002 Elsevier Science Ltd. All rights reserved.